The present invention relates to a battery with a positive electrode strip, a negative electrode strip, and a separator between the two rolled into a spiral electrode unit.
Considering charge collection, leads for the positive electrode strip and the negative electrode strip of prior art spiral electrode units are most often disposed at the center section of each respective electrode strip. Since each lead-to-electrode connecting region of a spiral electrode unit with this structure is in direct opposition to its counterpart, the lead connecting regions are covered with protective tape, insulating tape, or other material to prevent an internal short circuit. However, this means that a taping step to cover the lead connecting regions is required after lead attachment to the electrodes. This is an obstacle to making the manufacturing process continuous. Further, if external force is imposed on this type of battery and a defect such as a burr or flashing is present on the lead, the tape can be damaged allowing the possibility of internal shorting.
The present invention solves the problems described above by allowing simplification of spiral electrode unit processing and by preventing internal short circuits originating in the electrode lead region in a battery with a spiral electrode unit.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.